Does iPhone12 supports SA and Rel16 will be a SW upgrade only?

Devices
1

Does anyone know if iPhone12 supports SA already and if Rel16 will be a SW upgrade only?
(and not a chipset upgrade/new phone)

2

Yes, SA support is in china .

3

Does that mean handsets sold in EU are also SA compatible?
Any idea if phones can be flashed with new SW to make them Rel16 compliant?